///*
// * Licensed to the Apache Software Foundation (ASF) under one or more
// * contributor license agreements.  See the NOTICE file distributed with
// * this work for additional information regarding copyright ownership.
// * The ASF licenses this file to You under the Apache License, Version 2.0
// * (the "License"); you may not use this file except in compliance with
// * the License.  You may obtain a copy of the License at
// *
// *      http://www.apache.org/licenses/LICENSE-2.0
// *
// * Unless required by applicable law or agreed to in writing, software
// * distributed under the License is distributed on an "AS IS" BASIS,
// * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// * See the License for the specific language governing permissions and
// * limitations under the License.
// */
//package org.apache.catalina.core;
//
//import java.io.IOException;
//import java.security.Principal;
//import java.security.PrivilegedActionException;
//import java.util.Arrays;
//import java.util.Objects;
//import java.util.Set;
//import java.util.stream.Collectors;
//
//import jakarta.servlet.Filter;
//import jakarta.servlet.FilterChain;
//import jakarta.servlet.Servlet;
//import jakarta.servlet.ServletException;
//import jakarta.servlet.ServletRequest;
//import jakarta.servlet.ServletResponse;
//import jakarta.servlet.http.HttpServletRequest;
//import jakarta.servlet.http.HttpServletResponse;
//
//import org.apache.catalina.Globals;
//import org.apache.catalina.security.SecurityUtil;
//import org.apache.tomcat.util.ExceptionUtils;
//import org.apache.tomcat.util.res.StringManager;
//
///**
// * Implementation of <code>jakarta.servlet.FilterChain</code> used to manage the execution of a set of filters for a
// * particular request. When the set of defined filters has all been executed, the next call to <code>doFilter()</code>
// * will execute the servlet's <code>service()</code> method itself.
// *
// * @author Craig R. McClanahan
// */
//public final class ApplicationFilterChain
//        implements FilterChain {
//
//    // Used to enforce requirements of SRV.8.2 / SRV.14.2.5.1
//    private static final ThreadLocal<ServletRequest> lastServicedRequest = new ThreadLocal<>();
//    private static final ThreadLocal<ServletResponse> lastServicedResponse = new ThreadLocal<>();
//
//
//    // -------------------------------------------------------------- Constants
//
//
//    public static final int INCREMENT = 10;
//
//
//    // ----------------------------------------------------- Instance Variables
//
//    /**
//     * Filters.
//     */
//    private ApplicationFilterConfig[] filters = new ApplicationFilterConfig[0];
//
//
//    /**
//     * The int which is used to maintain the current position in the filter chain.
//     */
//    private int pos = 0;
//
//
//    /**
//     * The int which gives the current number of filters in the chain.
//     */
//    private int n = 0;
//
//
//    /**
//     * The servlet instance to be executed by this chain.
//     */
//    private Servlet servlet = null;
//
//
//    /**
//     * Does the associated servlet instance support async processing?
//     */
//    private boolean servletSupportsAsync = false;
//
//    /**
//     * Check the proper Servlet objects have been used.
//     */
//    private boolean dispatcherWrapsSameObject = false;
//
//    /**
//     * The string manager for our package.
//     */
//    private static final StringManager sm = StringManager.getManager(ApplicationFilterChain.class);
//
//
//    /**
//     * Static class array used when the SecurityManager is turned on and <code>doFilter</code> is invoked.
//     */
//    private static final Class<?>[] classType = new Class[]{ServletRequest.class, ServletResponse.class, FilterChain.class};
//
//    /**
//     * Static class array used when the SecurityManager is turned on and <code>service</code> is invoked.
//     */
//    private static final Class<?>[] classTypeUsedInService = new Class[]{ServletRequest.class, ServletResponse.class};
//
//
//    // ---------------------------------------------------- FilterChain Methods
//
//    /**
//     * Invoke the next filter in this chain, passing the specified request and response. If there are no more filters in
//     * this chain, invoke the <code>service()</code> method of the servlet itself.
//     *
//     * @param request  The servlet request we are processing
//     * @param response The servlet response we are creating
//     * @throws IOException      if an input/output error occurs
//     * @throws ServletException if a servlet exception occurs
//     */
//    @Override
//    public void doFilter(ServletRequest request,
//                         ServletResponse response) throws IOException, ServletException {
//
//        if (Globals.IS_SECURITY_ENABLED) {
//            final ServletRequest req = request;
//            final ServletResponse res = response;
//            try {
//                java.security.AccessController.doPrivileged((java.security.PrivilegedExceptionAction<Void>) () -> {
//                    internalDoFilter(req, res);
//                    return null;
//                });
//            } catch (PrivilegedActionException pe) {
//                Exception e = pe.getException();
//                if (e instanceof ServletException) {
//                    throw (ServletException) e;
//                } else if (e instanceof IOException) {
//                    throw (IOException) e;
//                } else if (e instanceof RuntimeException) {
//                    throw (RuntimeException) e;
//                } else {
//                    throw new ServletException(e.getMessage(), e);
//                }
//            }
//        } else {
//            internalDoFilter(request, response);
//        }
//    }
//
//    private void internalDoFilter(ServletRequest request,
//                                  ServletResponse response) throws IOException, ServletException {
//
//        // Call the next filter if there is one
//        if (pos < n) {
//            ApplicationFilterConfig filterConfig = filters[pos++];
//            try {
//                Filter filter = filterConfig.getFilter();
//
//                if (request.isAsyncSupported() && "false".equalsIgnoreCase(filterConfig.getFilterDef().getAsyncSupported())) {
//                    request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR, Boolean.FALSE);
//                }
//                if (Globals.IS_SECURITY_ENABLED) {
//                    final ServletRequest req = request;
//                    final ServletResponse res = response;
//                    Principal principal = ((HttpServletRequest) req).getUserPrincipal();
//
//                    Object[] args = new Object[]{req, res, this};
//                    SecurityUtil.doAsPrivilege("doFilter", filter, classType, args, principal);
//                } else {
//                    filter.doFilter(request, response, this);
//                }
//            } catch (IOException | ServletException | RuntimeException e) {
//                throw e;
//            } catch (Throwable e) {
//                e = ExceptionUtils.unwrapInvocationTargetException(e);
//                ExceptionUtils.handleThrowable(e);
//                throw new ServletException(sm.getString("filterChain.filter"), e);
//            }
//            return;
//        }
//
//        // We fell off the end of the chain -- call the servlet instance
//        try {
//            if (dispatcherWrapsSameObject) {
//                lastServicedRequest.set(request);
//                lastServicedResponse.set(response);
//            }
//
//            if (request.isAsyncSupported() && !servletSupportsAsync) {
//                request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR, Boolean.FALSE);
//            }
//            // Use potentially wrapped request from this point
//            if ((request instanceof HttpServletRequest) && (response instanceof HttpServletResponse) && Globals.IS_SECURITY_ENABLED) {
//                final ServletRequest req = request;
//                final ServletResponse res = response;
//                Principal principal = ((HttpServletRequest) req).getUserPrincipal();
//                Object[] args = new Object[]{req, res};
//                SecurityUtil.doAsPrivilege("service", servlet, classTypeUsedInService, args, principal);
//            } else {
//                servlet.service(request, response);
//            }
//        } catch (IOException | ServletException | RuntimeException e) {
//            throw e;
//        } catch (Throwable e) {
//            e = ExceptionUtils.unwrapInvocationTargetException(e);
//            ExceptionUtils.handleThrowable(e);
//            throw new ServletException(sm.getString("filterChain.servlet"), e);
//        } finally {
//            if (dispatcherWrapsSameObject) {
//                lastServicedRequest.set(null);
//                lastServicedResponse.set(null);
//            }
//        }
//    }
//
//
//    /**
//     * The last request passed to a servlet for servicing from the current thread.
//     *
//     * @return The last request to be serviced.
//     */
//    public static ServletRequest getLastServicedRequest() {
//        return lastServicedRequest.get();
//    }
//
//
//    /**
//     * The last response passed to a servlet for servicing from the current thread.
//     *
//     * @return The last response to be serviced.
//     */
//    public static ServletResponse getLastServicedResponse() {
//        return lastServicedResponse.get();
//    }
//
//
//    // -------------------------------------------------------- Package Methods
//
//    /**
//     * Add a filter to the set of filters that will be executed in this chain.
//     *
//     * @param filterConfig The FilterConfig for the servlet to be executed
//     */
//    void addFilter(ApplicationFilterConfig filterConfig) {
//
//        // Prevent the same filter being added multiple times
//        for (ApplicationFilterConfig filter : filters) {
//            if (filter == filterConfig) {
//                return;
//            }
//        }
//
//        if (n == filters.length) {
//            ApplicationFilterConfig[] newFilters = new ApplicationFilterConfig[n + INCREMENT];
//            System.arraycopy(filters, 0, newFilters, 0, n);
//            filters = newFilters;
//        }
//        filters[n++] = filterConfig;
//
//    }
//
//
//    /**
//     * Release references to the filters and wrapper executed by this chain.
//     */
//    void release() {
//        for (int i = 0; i < n; i++) {
//            filters[i] = null;
//        }
//        n = 0;
//        pos = 0;
//        servlet = null;
//        servletSupportsAsync = false;
//        dispatcherWrapsSameObject = false;
//    }
//
//
//    /**
//     * Prepare for reuse of the filters and wrapper executed by this chain.
//     */
//    void reuse() {
//        pos = 0;
//    }
//
//
//    /**
//     * Set the servlet that will be executed at the end of this chain.
//     *
//     * @param servlet The Wrapper for the servlet to be executed
//     */
//    void setServlet(Servlet servlet) {
//        this.servlet = servlet;
//    }
//
//
//    void setServletSupportsAsync(boolean servletSupportsAsync) {
//        this.servletSupportsAsync = servletSupportsAsync;
//    }
//
//
//    void setDispatcherWrapsSameObject(boolean dispatcherWrapsSameObject) {
//        this.dispatcherWrapsSameObject = dispatcherWrapsSameObject;
//    }
//
//
//    /**
//     * Identifies the Filters, if any, in this FilterChain that do not support async.
//     *
//     * @param result The Set to which the fully qualified class names of each Filter in this FilterChain that does not
//     *               support async will be added
//     */
//    public void findNonAsyncFilters(Set<String> result) {
//        for (int i = 0; i < n; i++) {
//            ApplicationFilterConfig filter = filters[i];
//            if ("false".equalsIgnoreCase(filter.getFilterDef().getAsyncSupported())) {
//                result.add(filter.getFilterClass());
//            }
//        }
//    }
//
//    @Override
//    public String toString() {
//        return Arrays.stream(filters).filter(Objects::nonNull).map(e -> e.getFilterName()).collect(Collectors.joining(" -> "));
//    }
//}
